Metal-bending machine.



ROBERT NAYSMITH, OF PITTSBURG, PENNSYLVANIA.

METAL-BENDING MACHINE.

Specification of Letters Patent.

Patented Sept. 17, 1907.

Application filed September 18,1906. erial No. 335,061.

i the United States of America, residing at Pittsburg, in

the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Metal-Bending Machines, of which the following is a specification, reference being had therein to the accompanying drawing. I

This invention relates to metal bending machines, and its object is to provide a machine for bending sheet metal strips into shape preparatory to forming them into tubes.

The invention comprises a machine of this character equipped with a plurality of sets of rolls whereby tube blanks of varying sizes may be formed, and a die or former of novel construction.

The construction of the improved device will be more fully described hereinafter in connection with the accompanying drawing, which forms part of this specification, and its novel features will be defined in the appended claims.

In the drawing, Figure 1 is a front elevation of a machine embodying the invention, Fig. 2 is a longitudinal section of the same, Fig. 3 is a front elevation enlarged of one pair of the rolls employed for giving the initial bend to the metal strip, Fig. 4 is a similar view of one pair of rolls for effecting the last step of the bending process, Fig. 5 is an elevation enlarged of the inner side of one of the die-plates, and Fig. 6 is a top plan view of the die employed.

The reference numerals 1 and 2 designate the sides or standards of the machine frame, provided with bearings for four parallel shafts 3, 4, 5 and 6.

Upon the front upper shaft 3 are mounted three rollers 7 each having a circumferential rib 8 of semi-circular form in cross-section, said rollers codperating with three rollers 9 mounted on thelower front shaft 4. Each of these rollers 7 and 9 is provided with independent oppositely projecting collars l0, adapting the rollers to be removed independently. Each pair of rollers 7 and 9 is of different width, the pair shown at the left of the machine being of less width than the center pair, while the pair shown at the right is wider than the center pair.

Upon the rear upper shaft 5 are mounted three rollers 11, each formed with a V-shaped peripheral groove 12, and upon the rear lower shaft 6 are mounted three rollers 13, each formed with a peripheral groove of semicircular form in cross section. Each of the pairs of rollers 11 and 13 varies in width to correspond to the alining pairs of rollers on the front shafts 3 and 4.

Between the front and rear pair of rollers is arranged a die comprising two oppositely disposed plates 14 and 15, recessed on their inner faces to provide over-hanging oppositely-disposed flanges beveled from front to rear to provide a flaring mouth 17, and having their forward ends recessed in reverse curves 18 to adapt them to extend forward in close proximity to the forward pair of rollers. One of these dies is provided for each set of four rolls, that is to say in the machine here shown comprising three pairs of rollers on the two front shafts, and three pairs of rollers on the two rear shafts, three of these improved dies are employed.

The operation of the machine constructed as thus described, is as follows: A strip of sheet metal 19 of predetermined width is passed between the rollers 7 and 9, and thus bent to semi-cylindrical form, and as the strip leaves said rollers it enters the flaring mouth of the die and passes through the rear opening of the die and thence between the rollers 11 and 13. In its passage through the die the edges of the strip are bent up to im part a cross-sectional contour of -U-shape to the strip after which the strip is passed through the rear rollers 11 and 13, which forces the edges of the strip together as illustrated in Fig. 4;

By providing a plurality of sets of rollers of varying widths tube blanks of different sizes may be formed in a single machine, and the novel construction of the die plates prevents buckling or distortion of the strip as it passes from one pair of rollers to the next pair.

Suitable gearing is provided for driving the rolls, such driving gear being indicated by dotted lines in Fig. 2.

The tube blank of the shape shown in Fig. 4 is adapted for further treatment in a finishing machine, to form it into a tube of cylindrical. form.

Having fully described my invention, what I claim as new is 1. In a metal bending device, forming rollers arranged in pairs, one roller of each pair having a semicircular peripheral groove and one of the opposing rollers of one pair having a semicircular periphery and the other opposing roller having a V-shaped peripheral groove and adapt ed to bend a strip of metal into semi-tubular form with the edges converging, and opposing die-members supported between said pairs of rollers with their confronting faces reversely recessed with the recesses decreasing in area toward the roller having the V-shaped groove, and with the portions of the confronting faces at one side of the dies adjacent to said converging edges separated sufiiciently to prevent compression thereof.

2. In a metal bending device, forming rollers arranged in pairs, one roller of each pair having a semicircular peripheral groove and one of the opposing rollers of one pair havinga semi-circular periphery and the other opposing roller having a V-shaped peripheral groove and adapted to bend a strip of metal into a semi-tubular form with the edges converging, and opposing die-members sup ported between said pairs of rollers with their confronting faces reversely recessed, with the recesses decreasing in area toward the roller having the V-shaped groove and with the contiguous portions of the dies at one side of the recesses separated sufliciently to prevent compression of the edges of the material passing through the rollers.

In testimony whereof I aiiix my signature in the presence of two Witnesses.

ROBERT NAYSMITH.

Witnesses K. H. BUTLER, MAX H. Snonovrrz. 

